Understand the role immigration played in the completion of the Transcontinental Railroad.

Immigration played a crucial role in the completion of the Transcontinental Railroad in the United States during the 19th century. The construction of the railroad required an enormous amount of labor, and immigrant workers provided a significant portion of this workforce.

Chinese immigrants, in particular, made up a large proportion of the workforce that built the Central Pacific Railroad, which was responsible for constructing the railroad from Sacramento, California, eastward. Facing immense challenges such as blasting through mountains and constructing bridges, the Central Pacific desperately needed workers who would be willing to work under difficult conditions for extended periods of time. Chinese immigrants, who were seeking better economic opportunities, were willing to endure the harsh conditions and low pay that were offered by the railroad companies.

The Central Pacific actively recruited Chinese immigrants, and by 1867, they made up nearly 90% of the workforce. Thousands of Chinese workers labored tirelessly, often under dangerous working conditions, to lay tracks, dig tunnels, and construct bridges. Their skill and hard work were essential in the completion of the railroad across the Sierra Nevada mountain range. Without the contribution of Chinese immigrants, it is unlikely that the Central Pacific would have been able to complete the railroad in the allotted time.

In addition to Chinese immigrants, other immigrant groups also made significant contributions to the Transcontinental Railroad. Irish immigrants, who had experience working on railroad construction in their homeland, played a crucial role in the construction of the Union Pacific Railroad from Omaha, Nebraska, westward. Irish laborers, known as "navvies," were skilled workers who endured grueling work conditions such as extreme weather, long working hours, and hazardous terrain.

Immigrant workers overall provided the essential manpower needed to overcome the numerous challenges faced during the construction of the Transcontinental Railroad. Their hard work, skills, and determination were vital in completing this massive engineering project, which connected the east and west coasts of the United States and had far-reaching impacts on the country's economic development, transportation, and westward expansion.